A Small Dose of Toxicology

By Steven G. Gilbert

in A Small Dose of Toxicology

Everyday, we come into contact with many relatively harmless substances that could, at certain concentrations, be toxic. This applies not only to obvious candidates such as asbestos, lead, and gasoline, but also to compounds such as caffeine and headache tablets. While the field of toxicology has numerous texts devoted to aspects of biology, chemistry, and mechanism of action, the need remains for a book that places toxicology within the framework of our daily lives.

A Small Dose of Toxicology presents the principles of toxicology by exploring the effects of common chemical agents such as caffeine, nicotine, and alcohol. It reviews the fundamentals of dose-response and factors of individual sensitivity in regard to these drugs, and then applies this knowledge to environmental contaminates such as lead, arsenic, pesticides, mercury, and radiation. Chapters discuss neurotoxicology, risk assessment, carcinogenicity, and with a variety of specific toxic agents, with each chapter designed as a self-contained module to allow for flexibility in the selection of personal or academic material.

Exploring current toxicology concerns within a human context, this text discusses how toxicology affects our everyday lives while providing insight into the broader issues of public health and disease prevention. Environmental and public health professionals, as well as novices and students requiring a basic foundation in toxicology will find this resource incredibly useful.

Animal Models in Toxicology

Edited By Shayne C. Gad, Shayne C. Gad

in Animal Models in Toxicology

Animal Models in Toxicology is a single-source reference for the use of animal models in toxicology. Chapters cover nine species used in toxicology and experimental biology. With contributions from experts in toxicology, toxicological pathology, and species-specific metabolism, each of these chapters provides an excellent introductory “course” along with guidance to the literature for a more detailed understanding.

This edition includes five new chapters. The first of these provides specific and detailed guidance on the humane, efficient, and effective performance of necropsies for laboratory animals. Other new chapters discuss new technologies available for laboratory animal research—imaging technologies, use of telemetry in animal studies, transgenic animal models, and immunology endpoint for assessment. Also provided is an overview of the increasingly complex laws and regulations that govern how laboratory animals are obtained, maintained, and utilized. A helpful appendix provides a quick guide to commercial sources of laboratory animals.

Advances in Entomotoxicology

Carlo P. Campobasso, Valentina Bugelli, Anna Carfora, Renata Borriello, Martin Villet

in Forensic Entomology

Forensic entomotoxicology deals mainly with the analysis of the tissues of insects to identify toxicants present in their food sources. Insects feeding on human tissues can ingest all of the xenobiotic substances taken by living individuals, such as common prescription and illicit drugs. Ecotoxicology is a well-established scientific discipline from which environmental forensic entomotoxicology is derived as a relatively new branch. Entomotoxicology also addresses the effects of drugs and toxins on arthropod development, survival, morphology, and their implications for estimating postmortem intervals. The primary focus of a forensic toxicologist is the detection of toxicants from human tissue samples to help in determining the cause of death. Like nutrients, toxicants encountered by an insect may be assimilated, digested, absorbed, and either sequestered, metabolized, or excreted. Entomological samples are currently of limited quantitative value in forensic toxicology.

Kratom exposures reported to United States poison control centers: 2011–2017

Published in Clinical Toxicology

Sara Post, Henry A. Spiller, Thitphalak Chounthirath, Gary A. Smith

From 2011 through 2017, 1807 kratom exposures were reported to United States PCCs. Almost two-thirds (65.0%) of these exposures occurred during 2016–2017. Most exposures occurred among adults ≥20 years (88.9%), males (70.8%), at a residence (86.1%), and were intentional (74.3%). Among first-ranked kratom exposures, 31.8% resulted in admission to a health care facility (HCF) and 51.9% in a serious medical outcome. Multiple-substance exposures were associated with greater odds of admission to a HCF (OR: 2.80; 95% CI: 2.21–3.55) and a serious medical outcome (OR: 2.25; 95% CI: 1.77–2.85) compared with single-substance exposures. There were 11 deaths associated with kratom exposure, including two that occurred after exposure to kratom only. Among kratom-only exposures, 86.1% resulted in one or more clinical effects. The most common clinical effects were agitation/irritability (22.9%) and tachycardia (21.4%). There were seven neonatal exposures, including five experiencing withdrawal.

Principles of Genetic Toxicology

Published in Drug and Chemical Toxicology

Wai Nang Choy

Genetic toxicology is the study of damages to the genes by chemical or physical agents. Damages to the genes (i.e., to DNA) if not repaired timely and correctly, change the DNA sequence and cause mutations. Mutations often result in the elimination or alteration of gene functions, and if the damages are not lethal, will lead to inheritable changes. Genotoxicity is thus customarily defined as the ability to damage DNA and to change DNA sequence. DNA sequence changes can be single nucleotide changes that result in point mutations, or multiple nucleotide changes that result in visible chromosomal aberrations. The adverse effect of a mutation is dependent on the gene and the tissue affected. The most serious effects of mutations in somatic cells are neoplasms, and in germ cells, inheritable neoplasms or birth defects.

The toxicology of chrysotile-containing brake debris: implications for mesothelioma

Published in Critical Reviews in Toxicology

Craig A. Poland, Rodger Duffin

The global use of “asbestos” in various commercial products has led to a wide range and pervasive legacy of disease. One such use of chrysotile asbestos was brake pads and was utilized commonly in automobiles and heavy vehicles. The result of incorporation of chrysotile into brake pads is associated with the exposure of mechanics fitting and servicing vehicles to liberated chrysotile fibers. Despite the proven exposure, the relative risk of malignant mesothelioma (MM) in this occupational population is broadly seen as low. The toxicity of particulates, including fibers such as chrysotile, is driven by a combination of dose and physicochemical properties. As such, it is plausible that chrysotile released from brake pads may have undergone modification, thereby altering the pathogenicity profile. The impact of high sheer stress causing shortening of long fibers, heat modification, binding of resin matrix to the fiber surface on the relative toxicity of brake debris with regards to MM is considered. It is apparent that released chrysotile can undergo significant modification, reducing the long fiber dose although not all modifications may lead to reduced toxicity.